Tank aggresion problem

[abominus]

i have four silver dollars,1 oscar, four irredescent sharks, i zebra tilapia (buttokoferi ciclid) and a raphael catfish in a 120 gallon tank. I now the space is small for them, so i am going to remove the four irredscent sharks. But the problem is my zebra tilapia. it keeps chasing my silver dollars and sometimes my oscar.the first time i put it, it messed up my oscar. it tore apart it's fins and the oscar looked pretty beat up. so i took out the oscar and treated it for one week. then i put it back and took out the zebra tilapia and kept in another tank for 1 week. after that i put it back with the lights closed since i have heard that if you put new ciclids together with the lights closed, they later think that they lived togather for their entire life.but when i turned on the lights, i saw that the oscar was sticking in one spot and one of it's fins looked a bit damaged. but the tilapia does not seem to chase it but whenever it gets close to the oscar, the oscar flees. And the silver dollars are still being chased. i added two caves also but not helping much. any advice?

 

[rcfishkeeping]

I would get rid of the tilapia. Those guys are pretty nasty and it’s a hit or miss with them. Other stock seems like they’ll be a lot better off without it.

 

[duanes]

The Heterotilapia buttikoferi will eventually kill everything in the tank.
That tank is not large enough for even 1 adult, they easily hit 20"., and are aggressive and territorial in that puddle.
It's barely large enough for 1 oscar, and the catfish.

 

[Midwater]

...since i have heard that if you put new ciclids together with the lights closed, they later think that they lived togather for their entire life.

I have never heard that. And what is more, it is totally ridiculous.

 

[neutrino]

after that i put it back with the lights closed since i have heard that if you put new ciclids together with the lights closed, they later think that they lived togather for their entire life.

Whoever told you that greatly exaggerated, but yes, there is that approach to adding new fish to a tank and yes it often helps, but not for species with elite aggression levels (like buttokeferi). There's also the approach of giving an aggressive fish a time-out in another tank, which sometimes works, but often doesn't. I don't know how often buttokeferi get 20 inches, a little less is more common, but keeping one with an oscar is like keeping a wildcat with a teddy bear and a time-out isn't going to fix it, considering how often buttokeferi are at or near the top of most aggressive cichlid lists.

 

[EricTheRed]

You need to rehome the Buttikofferi ASAP. If you want to keep it, you need at least a six foot, 125G tank, and will have to leave the Butti in there by himself/herself. Despite being highly aggressive, Buttikofferi are highly intelligent and make a great wet pet, but absent a 300 plus gallon tank, they cannot successfully be kept with other fish in most cases. Your Butti will be happy as will your remaining fish in your current tank if you give the Buttikofferi its own large tank/territory.